It is well known that compounds of formula I are useful as growth regulants. ##STR2## wherein R.sub.1 is alkyl of 1 to 3 carbon atoms or allyl; and M is ammonium, sodium, lithium or potassium.
For instance, the compounds of formula I and their utility as growth regulants are taught in U.S. Pat. No. 3,846,512, along with many related compounds.
It has been found that spray solutions of compounds of formula I which have been prepared in hard water have lower activity than spray solutions prepared in soft water. By hard water, it is meant generally water containing calcium and optionally magnesium ions in excess of 100 ppm hardness calculated as CaCO.sub.3. At 100 ppm hardness the effect is small. However, with increasing hardness it becomes more noticable. Many natural waters have greater hardness and significantly reduce the activity of compounds of formula I. Thus, a means for enhancing the effectiveness of the compounds of formula I in hard water is needed.